Paramagnetic resonance of Gd in single crystals of Pd in the very dilute limit and at high microwave frequency

Abstract

The ESR of 300- and 25-ppm Gd in single crystals of Pd at 35 and 9 GHz below 4.1 \ifmmode^\circ\else\textdegree\fi{}K is reported. It is shown that at 1.35 \ifmmode^\circ\else\textdegree\fi{}K and at 35 GHz a simple single-ion spectrum was obtained that is straightforward to analyze. The Gd collective resonance line (cluster line) at 35 GHz and 1.35 \ifmmode^\circ\else\textdegree\fi{}K shows a different behavior than at 9 GHz.